Tagged Questions

I'm developing a messenger application with encrypted chats.
In the first version of the app I've used PBKDF2 (10000 iterations, SHA1, random salt) to extend a short user password and generate keys ...

Okay so I have two options for how I would derive two keys for AES encryption and HMAC they are as follows:
Run BCrypt on a users passphrase and then use the bouncy castle implementation of HKDF in ...

I have an encryption scheme that uses a 256-bit master key, from which 2 separate keys (one for AES-256-CTR encryption and one for a HMAC-SHA256) are derived using HKDF. However, I'm not sure exactly ...

Note that this question is somewhat similar to Can I use my random IV (for AES) as a salt for PBKDF2?
My current encryption format computes two random PBKDF2 salts (encryption and HMAC, 8 bytes each) ...

I have heard that to combine two keys HKDF is better than using XOR function. But if you look at the HKDF RFC I could not figure out how to use it for concatenating two keys. What I can see is HKDF ...

I know how to calculate the entropy of a key that relates to its selection process. For example if the key space is $1000$, entropy of a randomly chosen key is $1000$. Suppose now you have two keys ...

Assume for the sake of the question that I have two variable-length bit strings, each with 128 bit cryptographic randomness, and I want to extract two 128 bit keys via HKDF-SHA256.
Which alternative ...

I am developing a mostly-offline authorization system that authorizes a user using an deterministically generated AuthKey derived from a MasterKey derived from a high-entropy chunk of data (128 bits) ...